Humans have been placing satellites into earth orbit since the launch of Sputnik 1 on Oct. 4, 1957. Most satellites placed in orbit are not designed or intended for recovery back on the earth. Indeed, the recovery of satellites from earth orbit is extraordinarily difficult and expensive. However, there are many situations wherein the intact recovery of particular satellites is desirable. For example, orbital experiments designed to test the effects of space on biological, chemical, or material properties may benefit from the retrieval of specimens placed in orbit.
Prior art systems for protecting physical payloads from the severe aerodynamic and thermal conditions during atmospheric reentry require the expense of initially lifting protective structures and materials to orbit. In some space systems intended for safe return to Earth, various mechanisms have been employed to slow the satellite sufficiently to effect reentry, using high-drag means for initially slowing the satellite through the atmosphere, and deploying parachutes and/or rocket systems for the final portion of the return. However, such systems are complex and relatively heavy.
Deployable aerobraking systems such as ballutes are disclosed in U.S. Pat. No. 4,504,031, “Aerodynamic Braking and Recovery Method for a Space Vehicle,” and U.S. Pat. No. 4,518,137, “Aerodynamic Braking System for a Space Vehicle,” by D. G. Andrews, both of which are hereby incorporated by reference in their entirety. These disclosures describe a gas deployed ballute system for placing a space system in low earth orbit, which additionally utilizes the vehicle's main rocket motor to produce cooling exhaust gases ahead of the vehicle on reentry.
There is a growing trend away from large and complex satellite systems and moving towards lower-cost, miniaturized, or small satellites. Advantages of small satellites are lower cost, lower weight (and hence lower launch costs), and ease of production. Moreover, miniaturized satellites enable missions that larger satellites are not suited for, such as constellations for data communications, the ability to work in coordination gathering data from different orbital locations, etc. For example, small satellites may be classified as: minisatellites (100-500 kg); microsatellites (10-100 kg); nanosatellites (1-10 kg), and picosatellites (<1 kg).
A particular standard for small satellites, referred to as the CubeSat Project, provides a standard for the design of nanosatellites to reduce cost and development time, increase accessibility to space, and sustain frequent launches, as discussed in CubeSat Design Specification Rev. 12, The CubeSat Program, California Polytechnic State University, which is hereby incorporated by reference in its entirety. The nominal 1 U CubeSat is a 10 cm cube with a mass of up to 1.33 kg. In some applications, two or more 1 U units are combined, or interconnected in a modular fashion, to produce a system.
An object of the invention is to provide a system for recovering small payloads and spacecraft using a deployed system that is of appropriate size to effect a completely passive reentry through the atmosphere of a planetary body and subsequent aerodynamic deceleration such that the spacecraft can be safely recovered without the use of a secondary deceleration system, such as a parachute.